Field
Integrated circuit package substrate.
Description of Related Art
An integrated circuit package package provides a number of functions for an integrated circuit chip including delivering power to the chip, transferring information into and out of the chip, dissipating heat and protecting the chip from physical and/or environmental damage. To the extent that the package substrate is damaged or defective, one or more of these functions can be impacted.
A typical chip package substrate includes a core substrate of a resin material having a thickness currently on the order of approximately 400 microns (μm) and below. The buildup layers of a dielectric material such as ABF insulating conductive routing layers to contact points on a surface of a package substrate for connection to an integrated circuit chip (a device side of the package substrate) and, representatively, routing layers to contact points on a back side of the package substrate for passive devices such as resistors and capacitors and to contact points for connection of the package substrate to another substrate such as a printed circuit board on an opposite side of the package substrate.
During the manufacturing of a package substrate, the package substrate can experience warpage. Excess convex warpage on a device side of a package substrate (curved outward) can cause open solder joint failure during reflow soldering to connect a chip to the package substrate. As substrate cores become thinner, a concern of warpage increases.